Used in a wide range of applications and industries from automotive to personal care, siloxanes are typically made by the hydrolysis of halosilanes or organohalosilanes. After hydrolysis, the siloxanes typically comprise residual impurities, such as acid or salt, which can be detrimental to the stability and performance of the siloxanes in various applications and which can be difficult to remove. For example, residual hydrogen chloride can potentially contribute to discoloration and viscosity increase upon aging.
Impurities have been removed in the past by traditional techniques involving dispersing the siloxane in an immiscible solvent, such as water, allowing the two immiscible liquids to coalesce and separate, and then removing the siloxane and solvent layers separately. However, dispersing the siloxane in solvent to the small droplet sizes necessary to provide an adequate interface between the two liquids requires large amounts of energy, and the coalescing and separating steps can require significant amounts of time. In addition, the removal efficiency is limited.
Therefore, there is a need for new methods of removing an impurity from a siloxane that require less energy, avoid lengthy coalescing and separation steps, and effectively remove the impurity.